Universal joint.



A. G. LAMB.

UNIVERSAL JOINT.

APPLIUATION FILED SEPT. 9. 1912.

1 l 22, 9 3 Patented Dec. 29, 1914.

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By his lltorne y, I

AMHERST G. LAMB, OF TORRINGTON, CONNECTICUT.

UNIVERSAL JOINT.

Specification of Letters Patent. Patented De 29 19141,,

Application filed September 9, 1912. SerialNo. 719,430.

To all whom it may concern:

Be it known that I, AMHERST G. LAMB, a oi tizen of the United States,residing in Torrington, in the county of Litchfield and State ofConnecticut, have invented certain new and useful Improvements inUniversal Joints, of which the following is a specification.

My invention discloses the correct use of the elasticity of metal inuniversal (balland-socket) joints to make them satisfactory in operationand as durable as possible with our present technique. In nature suchjoints comprise 'two bones one terminating in a ball, the othercontaining a socket; an elastic ligament limiting the play of the bonesand a synovial gland to oil them; and hitherto, in art, man has imitatednature and used metal without pausing to discover, by analysis, the bestmode of utilizing its qualities.

The only changes have been the use of metal, substitution of a tubularnut or union for the ligament and generally, omission of automaticoiling; except for wrist-pin joints, in which the ligament is replacedby a strap or yoke union and the socket is annular and divided. Jointsso constructed can be satisfactory xvhere the stress and strain arenever reversed because in such uses the ball is always pressed in onegeneral direction into its socket. axial play under load cannot ocourand the behavior of the union does not affect work-transmission. But fortransmitting reciprocation and stresses alternating in their generaldirections, such joints are apt to either bind, rattle or knock and areunsatisfactory and short-lived; and scientific adjustment of their fitand play to their uses is impossible, and must be left largely tochance; all because of the alternation, in the union, of compression andtensional elongation. All such defects are remedied in my inventionwhose characteristics are: two work-transmitting members adapted to beconnected. by a ball and socket and, connecting them, an adjustable,plural-membered union adapted to utilize the elastic reaction of metalagainst strain to enable the user to cause and to make permanentin thejoint (save as altered by wear) and entirely unaffected by the heaviestwork, the fit and plav most suitable for its user, so that it willneither bind, rattle nor knock. In the form illustrated the unionactsparallel with the axis of stress and-comprises a tension memherwhich envelops the bulb. and directly connects the two abutments of thesocket, and thereby the two work members; and an adjusting distenderwhich is a compression cushion interposed between said tension memberand one abutment of the socket and is adapted, when itself strained incompression, to cause a balancing tension'al strain in said tensionmember and extend it and dis tend the joint by separating the socketabutments a distance gaged by the dimensions and moduli of theelasticity of the tensional member and distender. and by the initialunit stress caused by adjustment.

If said initial stress be so great as to in duce in said members strainsconsiderably greater than would be caused by the greatest possibleworking stress, if they were strain-free, the Working stresses cause nochange whatever in the relations of the union and socket abutments andthe fit and play will be entirely unaffected (save by wear) under allwork conditions. In practice, the joint is adjusted by screwing thetension member home hard enough to cause in it the tension whichknowledge dictates; and then screwing home the distender until feelingreveals the proper fit and play in the joint.

It will be seen that my invention consists in a union adapted to applyto hall-andsocket joints the principle of limited stability due to theequilibrium of opposite forces (in this case elastic reactions) eachexceeding the maximum force to which the mechanism can be subjected inits uses.

In the accompanying drawing, showing one embodiment of my invention,Figure 1 is a side elevation; Fig. 2 is an axial section, some partsbeing shown in elevation; Fig. 3 is an end view of the device with theball member omitted; Fig. 4 is an end view of the sleeve member havingone divisional cut: Fig. 5 is a section through the sleeve; and. Fig. 6is a fragmentary view, enlarged, of some of the members.-

The device is shown as comprising a ball member having a ball 8 and astem 9, which ball is adapted to engage a work member 10 provided with astem 11 having at the end a face 12 preferably, but not necessarilycorresponding in curvature-to the ball 8, that engages the ball at itsend portion, that is, the portion opposite the stem 9. lihe face 12 canbe made a hollow cone or a plane. without materially impairing theefficiency or durability of the joint.

this end is smaller than the stem 11, whereby it can engage the ballaround the stem to press the ball into engagement with the end of thestem, and retain the ball seated thereon, when the sleeve is properlysecuredom the stem.

I further provide a distender, shown in the form of a sleeve 15, whoseprincipal function isto enable the user to establish and make permanentin the joint (save for wear) the fit and play best suited to its uses bymanipulating said distender so as to cause it to act as a compressioncushion between the stem 10 and the sleeve 13 (that is to say, betweenthe two socket-abutments or bearing faces of the joint) and to properlyand permanently distend the joint by setting up in said distender andsleeve respectively, equal initial compressive and tensile strains andelastic reactions thereagainst, acting parallel with the axis of stressand each considerably exceeding. the

greatest strain which would be caused in i said members, if strain-free,by the heaviest work to which the joint is liable. Further functions ofsaid distender are to lock the bearing sleeve 13 in its adjustedposition on the stem 11, and to embrace the sleeve and form a strongsupport for the same, which is of especial advantage when the sleeve isprovided with a longitudinal division. as at 42, in Fig. 4, or twolongitudinal divisions,

as at 16 and 17 in Fig. 3, whereby the sleeve is divided into twoportions.

. engaging faces of the ball, with the stem,

The means shown for adjustably securing the intermediate sleeve 13 onthe stem, comprises a screw thread engagement, the stem being providedwith threads 18, and the sleeve having a threaded bore .19 toturn on thestem. thereby adjusting the sleeve longitudinally on the stem. Thisprovides the proper adjustment between the said curved and with theannular bearing sleeve. To facilitate this adjustment, sockets-may beprovided to engage with a suitable spanner,

such as is shown at 20 in Fig. 5, or at 21, Fig. 4.

The distender 15 is shown as having its bore internally threaded as at22, and the sleeve 13 is externally threaded as shown at 23, whereby thedistender is adjustable longitudinally on the sleeve 13; and thedistender may have its outer face of hexagonal shape, as shown at 24, orotherwise formed, to be turned by a wrench or like means i a comparisonof the said screwed down upon the ball 8 until the proper tension iscaused in said sleeve, whereupon the distender 15 is screwed upon saidsleeve against the shoulder 25 until feeling reveals the proper fit andpiay in the joint; and said fit and play wili be per-- manent, save forwear.

Vhen properly adjusted, the joint is characterized by stability, whichis permanent relatively to the maximum working stress and due toopposite, balanced elastic reactions, parallel with the axis of stress,

in the distender and sleeve. The distender acts in compression, as acushion, causes balancing tension in the sleeve and properly andpermanently distends the socket. The play in such a joint must be veryslight, merely enough to make sure that the ball will never bind. Tofacilitate securing the proper play, the two sockets of the joint areseparated by a determined distance, as indicated by the dotted lines 10and 13, Fig. 2. Suppose this distance to be one-eighth of an inch, thematerial to be alloy steel with undulus of elasticity 28000000, elasticlimit 150000, and unit strain 112000, all in pounds per square inch;then the distention by adjustment of the lines 10 and 13 would be A29 g000000 s2000 It is obvious that the distender 15 also acts as a lock toprevent the sleeve 13 from aclUU working strain upon the bearingsurfaces normally tends to move the said bearing members. For instance,as will be seen by members as shown in the sectional view, Fig. 2, andof the stresses which occur therein as indicated by the arrows in Fig.6, any working stress between the ball and either of the said bearingfaces l-ii and 12 will normally tend to force the annular member 13(having the annular bearing face14) outwardly from the said centralbearing face 12 which is on the end j of the central threaded stem 11.If an external force be applied to the said annular bearing member 13 inthe direction indicatedby the arrow 2 in said sectional view, Fig. 6,1itwill be evident that the interlockinggscrew threads,-as 19 onthe insideof said annular member and the threads 18 on the outside of said stem,will necessarily come into engagement on the rearward side of thesaidcentral thread and on the forward side of the said thread 19 of saidannular member.

The above noted feature I have illustrated in the enlarged diagrammaticview given in Fig. 6, in which the said inner thread 19 is showncontacting on its forward side at 3 with the rearward side of the saidthread 18 of the-stem 11. Fig. 6 also illustrates the-co-action with theforegoing featureszof the external thread 23 of said annular bearingmember 13 with the abutment face 35, and the intervening distender 15,by means of which all of the parts, when properly adjusted, are held ina'rigid combination in proper working condition.

The said intervening distender 15, sets. or is itself bearing, againstthe forward face or abutment 35 of shoulder on the stem,

, and has an internal thread, as 22, Fig. 6,

engaging with the corresponding external thread 23 of said annularbearing member 13. The effect of this arrangement. as will now beobvious by "a comparison of the several figures of the drawing,including said diagrammatic Fig. 6, is such that when the annular memberis turned uponthe central stem 11 to the point of properly adjusting thefit or pressure thereof upon the ball journal 8, then by screwing downsaid distender [15 to bear firmly upon the abutment face 25, the forwardside of the thread 22 within said distender bears against the downwardside of the corresponding thread 23 ,on the exterior of said annularbearing member, as indicated, -for instance, at the justable bearing. Bythis means an ex-' t treme firmness ofadjustment is obtained and theseveral co-act ng parts of the socket are brought into a state ofintense stress whereby the bearing acquires, through being adjustedready for use, a high degree of initial resistance, so that in practice,when the usual working stresses are applied they do not operate to flexor impair the adjustment of the fit and play of the joint, because theycannot increase the initial strains, being themselves less than thestresses which caused said initial strains.

In some cases it is important to make the journal member curved in themannerindicated in Fig. 2, in which case the operating connectiontherefor and thereof may be arranged as also indicated in said Fig. 2,in which some suitable operating rod, as 30, is shown screwed into thethreaded bore of the extension 31 of said stem 9 of the journal member,a check nut as 32, being provided, if desired, for retaining the saidparts in their properly adjusted position. When the said journal memberis arranged as here set forth, obviously it cannot pass through theannular member 13 unless it be divided, and for this reason, amongothers, the said, member is shown in Fig. 3 to be entirely /divided,although it continues to act in the assembled connector as a singleannular bearing member so far as concerns the adjustment. When theannular hearing member 13 is thus constructed in two parts, as 33 and34, Fig. 5, these parts may be placed over the spherical journal 8 andthen this annular member'screwed into the distender 15 nearly to theproper working position, after which the central stem may be screwedinto the annular member and the several parts thus brought toapproximately their proper working positions. When this is accomplished,the said annular member may be adjusted after the manner of turning atubular screw upon the stem 11, and within the distender 15, until thefit or pressure from the spherical journal is slightly in excess of thatwhich is desired for the proper work ng condition of the same,

whereupon by means of suitable wrenches or the like, the distender 15should be brought back firmly against its" abutment face 25 for therebyputting all-of the said parts under the required stress, and therebymake theconnector ready for use.

As shown in Fig. 2,-the stem 9 of the ball member 8 is bent at rightangles to the aXis of the work member 10, which arrangement is used withthe intermediate sleeve 13 made in sections, to admit the insertion ofthe bent stem. But where the sleeve is not divided the stem is-madestraight, as 36, Fig. 1, that enter a socket 37 in a lever 4 and may besecured therein by a pin 43. \Vhen the several parts have been assembledin substantially the manner above outlined, it will be seen.

that all of the strains which occur within tically at zero by reason ofthe intensity of the stress which can be obtained by means of thepeculiar organization and method of adjustment which I have hereindescribed.

For convenience in operating the distender 15 relatively to the centralstem, the

exterior surface of this closing member may be of a hexagonal or othersuitable shape for engaging with a suitable wrench or spanner, and theabutment member 25 of the central stem may also be similarly formed fora like purpose, so that by using a 'pair of wrenches or like implementsin a well known manner, the necessary adjustment may bemade and all thethreaded members he firmly set in their proper positions with therequired degree of firmness for resisting the working forces and theintense vibrations met with in the automobile, and other mechanisms.

In practice, the central member 10 may have anv suitable extension, asfor instance, the bolt 40, whereby to apply the same to a working memberof a mechanism; or said central stem, together with its abutment face,may be formed and constitute a part of a lever arm, or other workingmember of the mechanical device to which the connector is to be a plied.In practice, however, and for reasons of convenience,-I prefer to makethe said central member with a bolt or threaded stem 40, with a nut, asell, in a well known manner.

In F i g. 1, the stem is shown as entering a socket 44 in a member 38,and secured by a binding screw 39.

Having thus described my invention, I claim 1. In a ball joint, a ballmember, a'work member comprising a threaded stem having a face adaptedto engage the ball, a sleeve internally threaded to screw on thethreaded stem and havingan internal face engaging the ball member toretain it seated on the stem, the sleeve being divided longitudinallv,and a distending second sleeve in engagement with the outer face of thefirst sleeve and also engaging the work member and adjustable on one ofsaid two members to effect a stress on the first sleeve in an out-' warddirection from the stem to lock it in adjusted positions thereon.

2. In a ball joint, a ball member, a work member comprising a stemhaving a face adapted to engage the ball, a sleeve member adjustablyengaging the stem and having an internal face engaging the ball toretain it seated on the stem, said sleeve being divided longitudinally,and a second sleeve in engagement with the outer face of the firstsleeve and also engaging the work member and adjustable on one of saidtwo members to effect a stress on the first sleeve in an outwarddirection from the stem to lock it in adjusted positions thereon. I

3. In a ball joint, a ball member, a work member comprising astem havinga face ada ted to engage the ball, a-sleeve externally threaded and adustably engaging the stem and having an internal face engaging the ballmember to retain it seated on the stem face, the-sleeve being dividedlongitudinally, the work member having a shoulder, and a seccnd sleeveinternally thi eaded to screw on the said first sleeve and engaging saidshoulder by one end to lock the first sleeve in adjusted positions onthe stem.

4:. In aball joint, a ball member, a Work member comprising a threadedstem having a face adapted to engage the ball, a sleeve externallythreaded and also internally threaded to screw on the threaded stem and.

having an internal face engaging the ball member to retain it seated onthe stem face, said sleeve being dividedlongitudinally, the Work memberhaving a shoulder, and a distendiiig second sleeve internallyf threadedto screw onthe said first sleeve and engaging said shoulder by one endto lock the firsL sleeve in adjusted positions on the stem.

5. In a ball joint, a ball member, a work member comprising a threadedstem having a face adapted to engage the ball. a sleeve internallvthreaded to crew on the threaded AMHERST G. LAMB.

Witnesses:

JAs. E. MALLETT, L. B. SPEED.

